[R-390] Cleaning volume control

k2cby k2cby at optonline.net
Sat Mar 19 12:52:36 EDT 2011


De-Ox-It is great for switches, relays, plugs, jacks, tube sockets and other
metal-to-metal contacts, but I have 
never had good luck using on carbon volume controls - it sometimes dissolves
the carbon 
or whatever binder is used to adhere the carbon dust.

My favorite treatment for carbon pots is ordinary "TV tuner" cleaner/lube
spray from Radio Shack.

If you are cleaning a mil-spec quality sealed pot (Type "AB" or "Type J"),
you can drill a 1/16 (or smaller) hole 
in the back, shoot in the solvent, shake it out and either solder the drill
hole shut or cover it with tape.

Lesser-quality pots (even if "sealed") can be opened by judiciously prying
up the tabs on either side of the 
bushing (usually 2 tabs on each side) that hold the rear cover to the front
plate. Use slip-jointed pliers to close 
the tabs when you are finished.

Miles B. Anderson, K2CBY
16 Round Pond Lane
Sag Harbor, NY 11963
Tel.: (631) 725-4400
Fax.: (631) 725-2223
e-mail: k2cby at optonline.net 




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